1. Field of the Invention
The present invention relates to novel coated metal articles, in particular coated, untreated, bright, sealed, anodized metal sheets, especially coated bright, sealed, anodized aluminum sheets. The present invention also relates to methods for coating metal articles, in particular untreated, bright, sealed, anodized metal sheets, especially bright, sealed, anodized aluminum sheets. The present invention further relates to laminated composites which contain such a coated metal article, and methods for preparing such laminated composites.
2. Discussion of the Background
Unsealed metal substrates which have been anodized by an electrochemical process employing sulfuric acid, chromic acid, phosphoric acid, or oxalic acid electrolytes, provide an excellent base for adhesion of a paint, enamel or lacquer coating because of the porosity of the anodized metal surface. Clear methacrylate lacquers are known to be useful to paint such unsealed, anodized metal surfaces to provide a high gloss coating.
However, anodized metal substrates are often sealed when it is desired to employ the metal in an environment where the porosity of the anodized metal is undesirable, such as for example when used in auto trim parts where exposure to the elements can result in corrosion or staining of the metal. Sealing of such anodized metal substrates, such as by immersion in boiling deionized water, sodium bichromate, nickel acetate solutions, or steam, makes the anodized coating on the metal nonabsorptive by closing down or plugging the pore structure of the anodized coating. When anodized metal substrates have been sealed, it is very difficult for paint or a coating to adhere to the surface of the sealed, anodized metal substrate, particularly untreated bright, sealed, anodized metal substrates, even more particularly untreated, bright, sealed, anodized aluminum substrates.
U.S. Pat. No. 5,178,915 discloses the coating of untreated, bright, sealed anodized metals such as aluminum coils, with a catalyst-free coating composition, which contains a high gloss, thermosetting, hydroxyl group-containing fluorocarbon polymer (such as a fluorinated ethylene vinyl ether, FEVE), a crosslinking agent, a solvent, an ultraviolet screening agent, and an ultraviolet stabilizer. However, the coating of U.S. Pat. No. 5,178,915 specifically excludes inclusion of a catalyst to impart the necessary properties. In addition, U.S. Pat. No. 5,178,915 uses very high temperatures ( greater than 450xc2x0 F.) both for the coil coating and curing processes.
U.S. Pat. No. 5,366,803 discloses metal sheets having a layer of cured polyvinylidene fluoride (PVDF) paint on the metal surface and a layer of cured FEVE on the cured layer of PVDF and laminated composites prepared from such metal sheets. However, it is desirable that coatings provide a mirrored finish with a high gloss, i.e. produce at least 99 percent reflectance, and the coatings of U.S. Pat. No. 5,366,803 have a gloss of only 25 to 80%.
Various composite laminates are known wherein a metal sheet is laminated on a thermoplastic synthetic resin sheet. U.S. Pat. No. 4,508,425 discloses a mirror manufactured by plating chromium on one surface of a metal sheet which bonded to a synthetic resin sheet, to form a mirror surface. The mirrored-finish sheet may be worked to a desired shape and may be formed with a decorative pattern U.S. Pat. No. 4,560,623 discloses a specular product of bronze-like tone particularly suitable for use as a decorative material. The specular product uses, as a substrate, a composite comprising a synthetic resin sheet and metal sheets laminated thereon, and includes a nickel deposit plated on the metal sheet and a specular film of Snxe2x80x94Ni alloy electroplated on the nickel deposit using a specific electroplating bath.
Such laminates are useful for a number of architectural applications, because the laminates combine light weight with high strength. These laminates may be used as finished surfaces for all or some portions of the interior or exterior surfaces of a building.
However, when metal sheets are coated with conventional polyvinylidene fluoride (PVDF) paints, the coated plates exhibit a phenomenon known as heat blocking upon subsequent lamination with a resin layer. This heat blocking phenomenon seriously detracts from the aesthetic appeal of the finished plate. In addition, use of conventional PVDF paints results in coatings which have a gloss within a fairly narrow range, 25 to 35%.
Thus, there remains a need for coated metal articles, in particular coated untreated, bright, sealed, anodized metal sheets, especially coated bright, sealed, anodized aluminum sheets, which overcome the above-described deficiencies. There also remains a need for coated metal sheets with a high degree of gloss or reflectance, which do not experience heat blocking on lamination, which exhibit excellent weathering resistance, and which are able to be bent to a sharp angle without cracking of the coating on the exposed metal surface. There also remains a need for laminates which contain such a coated metal sheet. There also remains a need for methods for preparing such coated metal articles and such laminates.
Thus, it is one object of the present invention to provide novel coated metal articles.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets in coil form.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets in coil form.
It is another object of the present invention to provide novel coated metal articles, which exhibit a high gloss.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit a high gloss.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit a high gloss, in coil form.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit a high gloss.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit a high gloss, in coil form.
It is another object of the present invention to provide novel coated metal articles, which exhibit a high reflectance.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit a high reflectance.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit a high reflectance, in coil form.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit a high reflectance.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit a high reflectance, in coil form.
It is another object of the present invention to provide novel coated metal articles, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%, in coil form.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%, in coil form.
It is another object of the present invention to provide novel coated metal articles, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%, in coil form.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit a reflectance of at least 87% or a gloss rating of at least 99%, in coil form.
It is another object of the present invention to provide novel coated metal articles, whereby the resulting coating has sufficient integrity and adhesion to the metal article, to allow post-coating fabrication of the coated metal article into a laminate, particularly a laminate for use as a building panel.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, whereby the resulting coating has sufficient integrity and adhesion to the metal article, to allow post-coating fabrication of the coated metal article into a laminate, particularly a laminate for use as a building panel.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets in coil form, whereby the resulting coating has sufficient integrity and adhesion to the metal article, to allow post-coating fabrication of the coated metal article into a laminate, particularly a laminate for use as a building panel.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, whereby the resulting coating has sufficient integrity and adhesion to the metal article, to allow post-coating fabrication of the coated metal article into a laminate, particularly a laminate for use as a building panel.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets in coil form, whereby the resulting coating has sufficient integrity and adhesion to the metal article, to allow post-coating fabrication of the coated metal article into a laminate, particularly a laminate for use as a building panel.
It is another object of the present invention to provide novel coated metal articles, which exhibit good weathering resistance and are able to be bent to a sharp angle without cracking of the coating on the exposed surface of the metal.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit good weathering resistance and are able to be bent to a sharp angle without cracking of the coating on the exposed surface of the metal.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit good weathering resistance and are able to be bent to a sharp angle without cracking of the coating on the exposed surface of the metal, in coil form.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit good weathering resistance and are able to be bent to a sharp angle without cracking of the coating on the exposed surface of the metal.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit good weathering resistance and are able to be bent to a sharp angle without cracking of the coating on the exposed surface of the metal, in coil form.
It is another object of the present invention to provide novel coated metal articles, which exhibit sufficient stability and integrity to resist corrosion, hazing, cloudiness, flaking, cracking, mottling and/or delamination of the coating when exposed to environmental factors such as smog, ultraviolet light, ozone, and excessive heat and cold, and abrasive cleaning solutions.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets, which exhibit sufficient stability and integrity to resist corrosion, hazing, cloudiness, flaking, cracking, mottling and/or delamination of the coating when exposed to environmental factors such as smog, ultraviolet light, ozone, and excessive heat and cold, and abrasive cleaning solutions.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized metal sheets in coil form, which exhibit sufficient stability and integrity to resist corrosion, hazing, cloudiness, flaking, cracking, mottling and/or delamination of the coating when exposed to environmental factors such as smog, ultraviolet light, ozone, and excessive heat and cold, and abrasive cleaning solutions.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets, which exhibit sufficient stability and integrity to resist corrosion, hazing, cloudiness, flaking, cracking, mottling and/or delamination of the coating when exposed to environmental factors such as smog, ultraviolet light, ozone, and excessive heat and cold, and abrasive cleaning solutions.
It is another object of the present invention to provide novel coated untreated, bright, sealed, anodized aluminum sheets in coil form, which exhibit sufficient stability and integrity to resist corrosion, hazing, cloudiness, flaking, cracking, mottling and/or delamination of the coating when exposed to environmental factors such as smog, ultraviolet light, ozone, and excessive heat and cold, and abrasive cleaning solutions.
It is another object of the present invention to provide a novel composite laminates which contains such a coated metal article, in particular such a coated, untreated, bright, sealed, anodized metal sheet, especially such a coated bright, sealed, anodized aluminum sheet.
It is another object of the present invention to provide novel composite laminates which contain a coated metal sheet and which may be bent to a sharp angle without cracking of the coating.
It is another object of the present invention to provide novel composite laminates which contain a coated metal sheet, in which the exposed metal sheet exhibits a reflectance of at least 87% or a gloss rating of at least 99%.
It is another object of the present invention to provide novel composite laminates which contain a coated metal sheet, in which the exposed metal sheet exhibits a reflectance of at least 87% or a gloss rating greater than 99%.
It is another object of the present invention to provide novel composite laminates which contain a coated metal sheet, which exhibits excellent weathering resistance.
It is another object of the present invention to provide novel methods for preparing such coated metal articles.
It is another object of the present invention to provide novel methods for preparing such composite laminates These and other objects, which will become apparent during the following detailed description, have been achieved by the inventors"" discovery that coated metal articles, comprising:
(a) a metal substrate with a surface; and
(b) a layer of a cured fluorinated ethylene vinyl ether paint on said surface,
xe2x80x83wherein said layer of cured fluorinated ethylene vinyl ether paint is formed by coating said surface with a coating composition which comprises:
(axe2x80x2) a fluorinated ethylene vinyl ether;
(bxe2x80x2) a curing agent;
(cxe2x80x2) a catalyst; and
(dxe2x80x2) a solvent,
and curing said coating composition, achieve the forgoing objectives.
The inventors have also discovered that such coated metal articles may be prepared by a method comprising the steps:
(1) coating a surface of the metal article with a coating composition which comprises:
(axe2x80x2) a fluorinated ethylene vinyl ether;
(bxe2x80x2) a curing agent;
(cxe2x80x2) a catalyst; and
(dxe2x80x2) a solvent, to obtain an uncured coating layer
and
(2) curing said uncured coating layer.
The inventors have also discovered that metal-resin composite laminates comprising:
(A) a resin sheet; and
(B) a first metal sheet laminated on a first surface of said resin sheet;
xe2x80x83wherein said first metal sheet is a coated metal sheet comprising:
(a) a metal substrate with an interior and exterior surface; and
(b) a layer of a cured fluorinated ethylene vinyl ether paint on said exterior surface opposite said resin sheet,
xe2x80x83wherein said layer of cured fluorinated ethylene vinyl ether paint is formed by coating said exterior surface with a coating composition which comprises:
(axe2x80x2) a fluorinated ethylene vinyl ether;
(bxe2x80x2) a curing agent;
(cxe2x80x2) a catalyst; and
(dxe2x80x2) a solvent,
and curing said coating composition,
achieve the above-mentioned objectives.
The inventors have also discovered that such metal-resin composite laminates may be prepared by a process comprising:
(1) forming a layer of a coating composition on a metal surface; and
(2) curing said layer of said coating composition, to obtain a coated metal sheet; and
(3) laminating said coated metal sheet to a resin sheet,
xe2x80x83wherein said coating composition comprises:
(axe2x80x2) a fluorinated ethylene vinyl ether;
(bxe2x80x2) a curing agent;
(cxe2x80x2) a catalyst; and
(dxe2x80x2) a solvent.